Application of correlation analysis of terahertz spatial light modulator patterns to improve the quality of ghost imaging

Terahertz (THz) radiation has unique properties that make it promising for a wide range of applications, including medical diagnostics, non-destructive testing, and security. However, existing multi-pixel cameras have limitations in sensitivity and resolution. The ghost imaging (GI), which utilises a single-pixel detector and a spatial light modulator (SLM), makes it possible to overcome these limitations. One of the features of THz SLM is that the pixel size is comparable to the wavelength, which can lead to significant diffraction distortions. In order to improve the quality of the reconstructed images, this work optimizes the ghost imaging method using correlation analysis of terahertz spatial modulator patterns. In particular, the efficiency of the selection of lighting patterns based on various orthogonal matrices, such as discrete Fourier transform, discrete cosine transform, Hadamard transform and Haar transform, is analyzed. It is also shown that correlation analysis enables the selection of subpixel scanning strategy for super-resolution imaging. Thus, it is shown that correlation analysis is an effective way to evaluate the quality of optical systems for ghost imaging.